Q. A 5-year-old girl is brought to the physician’s office in the month of June by her parents who report that their daughter has developed several circular, red, expanding rashes with central clearing on her legs and arms over the past week. They live near a wooded area and recall removing a tick from her skin about two weeks ago. The child has no fever, headache, joint pains, or any neurological symptoms. The parents deny any recent travel history. On physical examination, the physician notes three erythema migrans lesions of about 5 cm diameter each, but the rest of the examination, including a neurological and cardiac exam, is unremarkable. What is the most appropriate first-line antibiotic choice for this patient?